An image of an 87-year-old driver who failed an eye test carried out by police officers at the roadside.
Photograph: PA

A police crackdown on drivers with defective vision has been launched that will see every driver who fails a roadside eye test immediately lose their licence.

All motorists stopped by police officers from three forces in September will be required to read a number plate from 20 metres. If they cannot, they will have their licence revoked on the spot.

Data from the tests will be used to improve understanding of the extent of poor driver vision.

The initiative is being run by forces in Thames Valley, Hampshire and the West Midlands, and is supported by the road safety charity Brake and opticians Vision Express.

Sgt Rob Heard, representing the police forces taking part in the campaign, said: “Not being able to see a hazard or react to a situation quickly enough can have catastrophic consequences.”

He warned that officers would be carrying out eyesight checks “at every opportunity”.

Officers can request an urgent revocation of a licence through the DVLA if they believe the safety of other road users will be put at risk if a driver remains on the road.

The power was introduced in 2013 under Cassie’s Law, named after 16-year-old Cassie McCord, who died when an 87-year-old man lost control of his vehicle in Colchester, Essex.

It later emerged he had failed a police eyesight test days earlier, but a legal loophole meant he was allowed to continue driving.

Brake and Vision Express are calling for a recent eye test to be required when licences are renewed every 10 years.

Under current rules, the only mandatory examination of vision takes place during the practical test, when learners must read a number plate from 20 metres. Once someone has obtained their licence, it is up to them to tell the DVLA if they have a problem with their eyesight.

Joshua Harris, director of campaigns for Brake, said: “It is frankly madness that there is no mandatory requirement on drivers to have an eye test throughout the course of their driving life.

“Only by introducing rigorous and professional eye tests can we fully tackle the problem of unsafe drivers on our roads.”

Research by the Association of Optometrists published in November last year found that more than a third (35%) of optometrists saw patients in the previous month who continued to drive despite being told their vision was below the legal standard.